Data available for determining azimuth value of Traffic Alert Collision Avoidance System (TCAS) consists of raw TCAS data sampled at 1 Hz, all ownship data provided at mission computer rates, and Inertial Reference Unit (IRU) data from an othership reported over a standard Automatic Dependent Surveillance Broadcast (ADS-B) data-link at 2 Hz. TCAS and/or IRU data alone do not provide sufficient accuracy and precision to maintain flight formation within desired limits. Current TCAS devices provide reported azimuth data having a RMS (root mean square) error in the range of 6 to 7 degrees.
An improved TCAS azimuth computing device with smaller error is desirable for increased flight formation capability.